Midget radio receiver



March 23, 1937. P. s. BESHORE Filed March 5, 1936 Patented Mar. 23, 1937i'i'ED STATES TENT FEE

Application March 5,

5 Claims.

This invention appertains to new and useful improvements in the generalart of radiant energy and more particularly to a radio receiver of thecrystal type.

5 The principal object of the present invention is to provide a receiverof very small proportions so that the same can actually be placed in thevusers pocket and carried about from place to place with ease.

Another important object of the invention is to provide a midget typereceiver of the crystal type wherein the crystal is fixed, thuseliminating the requirement of readjustment.

Another important object of the invention is 15 to provide a midgetradio receiver which involves only one adjustment for reception.

Other important objects and advantages of the invention will becomeapparent to the reader of the following specification.

In the drawings:

Figure 1 represents a perspective view of the instrument.

Figure 2 represents a perspective view of one section of the case.

Figure 3 represents a perspective view of the top section of the case.

Figure 4 represents a perspective view of the coil block.

Figure 5 is a perspective view of the front plate 30 and associatedcontact fingers.

Figure 6 is a longitudinal sectional view through the coil plug.

Figure 7 is a diagrammatic view disclosing the electrical connectionbetween the electrical de- 35 vices involved.

Referring to the drawings wherein like numerals designate like parts, itcan be seen that numeral 5 represents a rectangular shaped block ofsubstantially rectangular shape in cross sec- 40 tion, the same havingan enamel wire coil 3 wound thereon for a major portion of its length.One end of the block 5 (which may be wood or some dielectriccomposition) has a recess I therein from the bottom of which extends abore 8 45 entirely through the block and having a spring contact finger9 protruding thereinto. This finger has a laterally disposed lug ID atits outer end secured by a small brad Ii to the adjacent end of theblock 5 and from this lug l extends the jumper l2 to the adjacent end ofthe coil 6,

the opposite end of the coil 6 being free.

At the same end of the block 5 as the contact finger 9 is the short borel3 having the spring contact finger l4 protruding therein, this finger55 54 extending laterally from the arm l5 at one 1936, Serial No. 67,391

end of the front plate l6, which front plate is of current conductivematerial. The opposite end of the plate it is provided with the arm iiand contact finger l8 extending inwardly from the arm ll which protrudesinto the short bore It at the opposite end of the block 5, whileadjacent this short bore i9 is the short bore 20 in which is located thespring contact finger 2! having a lug 22 at its outer end secured to theblock by a brad 23.

Disposed through the recess 1 and driven into the bore 8 is the screw24, the head 25 of which has a solder deposit 26 thereon in which a sensitive crystal 2'! is embedded. A cats whisker 28 secured in place by abrad 29 engages this crystal 2'! and as is shown in Figure 6, a jumper30 extends from the spring contact finger 2| to this brad 29. A depositof pitch 3| or some other suitable material is placed in this recess 1so as to seal and retain the parts in the recess 1 in the definiteposition shown so that the cats whisker cannot become displaced from thetested sensitized portion of the crystal.

A front plate I6 is provided with a nut 33 thereon and this plate It issecured over the plate of insulation 34 located on the front of theblock 5.

A cardboard or bakelite container consists of the bottom section 35 forreceiving the block 5 and the slip type cover 36 which engages over thesides of the bottom section 35.

The top of the 'cover 36 is provided with a semicircular shaped opening37 around the curved edge of which are suitable graduations 38. Anopening 39 is located in the top of the cover 36 through which the screw40 of the knob 4i extends to engage into the nut 33 on the plate Hi. Thecontactor 42 which extends laterally from this screw 46 has thelaterally disposed contact 43 on its free end for wiping engagement withthe arcuate shaped cleared portion 44 of the coil 6.

Openings are formed in the ends of the sections 35, 35 of the housing sothat the plugs 44-44 of an ear phone 45 can be plugged into the openingI926 to engage the contact fingers l8-2|, and an antenna plug 46 and aground plug 45 engaged into the opening i38 to engage the contactfingers 3-9 respectively.

While the foregoing specification sets forth the invention in specificterms, it is to be understood that numerous changes in the shape, sizeand materials may be resorted to without departing from the spirit andscope of the invention as claimed hereinafter.

Having thus described the invention, what is claimed as new is:

1. In a radio receiver, a body having the property of insulation, atuning coil on the body, a strip of insulation and a metallic stripdisposed across the coil and having their ends secured to the body, anda contactor held against the metallic strip and shaped to engage withthe coil for tuning purposes.

2. In a radio receiver, a body having the property of insulation, atuning coil on the body, a strip of insulation disposed across the coiland having its ends secured to the body, and a contactor secured againstthe strip and shaped to engage with the coil for tuning purposes, saidbody having recesses therein, a conductor strip disposed along theoutside of the strip of insulation, said contactor being carried by theconductor strip, and spring contact members disposed into the recessesand connected to said conductor strip, said spring contact members andrecesses defining electrical sockets.

3. In a radio receiver, a body having the property of insulation, atuning coil on the body, a strip of insulation disposed across the coiland having its ends secured tothe body, and a contactor secured againstthe strip and shaped to engage with the coil for tuning purposes, saidbody having recesses therein, a conductor strip disposed along theoutside of the strip of insulation, said conductor strip beingelectrically connected with the contactor and provided with Springcontact members extending therefrom and into said recesses to cooperatewith the recesses to define electrical sockets.

4. In a radio receiver, a tuning coil core having the property ofinsulation, said core having a recess therein, a fixed detector mountedin the recess, and a sealing material embedding a portion of thedetector to hold the same in adjusted position, said fixed detectorconsisting of a screw driven into the inner wall of the said detectorrecess and having a detector crystal fastened thereto, and a contactmember disposed against the crystal at a sensitized place thereon, saidcrystal and contact member being embedded in said sealing material.

5. In a radio receiver, a tuning coil core having the property ofinsulation, said core having a recess therein, a fixed detector mountedin said recess, and a sealing material embedding a portion of thedetector to hold the same in adjusted position, said fixed detectorconsisting of a conductor embedded in the wall of said detector recessand having a detector crystal electrically connected thereto, and acontact member disposed against the crystal at a sensitized placethereon, said crystal and contact member being embedded in said sealingmaterial.

PAUL S. BESHORE.

